package com.ruoyi.framework.aspectj;

import com.ruoyi.common.annotation.RateLimiter;
import com.ruoyi.common.enums.LimitType;
import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.common.utils.ServletUtils;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.common.utils.ip.IpUtils;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Component;

/**
 * 限流处理
 *
 * @author ruoyi
 */
@Aspect
@Component
public class RateLimiterAspect {
  private static final Logger log = LoggerFactory.getLogger(RateLimiterAspect.class);

  private RedisTemplate<Object, Object> redisTemplate;

  private RedisScript<Long> limitScript;

  @Autowired
  public void setRedisTemplate1(RedisTemplate<Object, Object> redisTemplate) {
    this.redisTemplate = redisTemplate;
  }

  @Autowired
  public void setLimitScript(RedisScript<Long> limitScript) {
    this.limitScript = limitScript;
  }

  @Before("@annotation(rateLimiter)")
  public void doBefore(JoinPoint point, RateLimiter rateLimiter) throws Throwable {
    String key = rateLimiter.key();
    int time = rateLimiter.time();
    int count = rateLimiter.count();

    String combineKey = getCombineKey(rateLimiter, point);
    List<Object> keys = Collections.singletonList(combineKey);
    try {
      Long number = redisTemplate.execute(limitScript, keys, count, time);
      if (StringUtils.isNull(number) || number.intValue() > count) {
        throw new ServiceException("访问过于频繁，请稍候再试");
      }
      log.info("限制请求'{}',当前请求'{}',缓存key'{}'", count, number.intValue(), key);
    } catch (ServiceException e) {
      throw e;
    } catch (Exception e) {
      throw new RuntimeException("服务器限流异常，请稍候再试");
    }
  }

  public String getCombineKey(RateLimiter rateLimiter, JoinPoint point) {
    StringBuffer stringBuffer = new StringBuffer(rateLimiter.key());
    if (rateLimiter.limitType() == LimitType.IP) {
      stringBuffer.append(IpUtils.getIpAddr(ServletUtils.getRequest())).append("-");
    }
    MethodSignature signature = (MethodSignature) point.getSignature();
    Method method = signature.getMethod();
    Class<?> targetClass = method.getDeclaringClass();
    stringBuffer.append(targetClass.getName()).append("-").append(method.getName());
    return stringBuffer.toString();
  }
}
